Monocyte heterogeneity in cardiovascular disease

Area of Science:

• Immunology
• Cardiovascular Biology
• Cellular Heterogeneity

Background:

• Monocytes are key immune cells differentiating into macrophages (MФ), playing roles in cardiovascular disease (CVD) pathogenesis.
• Current monocyte classification into classical (cMo), intermediate (intMo), and non-classical (ncMo) subsets based on CD14 and CD16 expression shows altered distributions in CVD.
• The causal role and predictive value of specific monocyte subsets in CVD remain unclear, despite associations with conditions like atherosclerosis and heart failure.

Purpose of the Study:

• To review current knowledge on monocyte heterogeneity in homeostasis and disease, particularly in the context of CVD.
• To explore the functional differences between macrophage (MФ) populations derived from distinct monocyte subsets.
• To highlight the implications of monocyte subset heterogeneity for cardiovascular health and disease.

Main Methods:

• Literature review of recent high-parameter cytometry and single-cell RNA sequencing (scRNA-Seq) studies.
• Analysis of existing data on monocyte subset distribution in cardiovascular disease.
• Synthesis of findings on monocyte-derived macrophage (MФ) functionality.

Main Results:

• Monocyte subsets exhibit significant heterogeneity, with intermediate monocytes (intMo) frequently associated with CVD.
• Emerging evidence suggests functional disparities between MФ derived from different monocyte subsets.
• Current classification may not fully capture the complexity of monocyte heterogeneity and its role in CVD.

Conclusions:

• Understanding the functional diversity of monocyte subsets is crucial for elucidating their role in CVD pathogenesis.
• An updated nomenclature and further functional studies are necessary to clarify the specific contributions of each monocyte subset to cardiovascular disease.
• Targeting specific monocyte subsets or their differentiated MФ populations may offer novel therapeutic strategies for CVD.